Dynamic Analysis And Simulation Of Conjugate Cam Weft Insertion Mechanism Of High Speed Rapier Loom

With the development of rapier loom towards lightweight and high speed,the dynamic performance of weft insertion mechanism affects the weaving quality and efficiency of rapier loom.Domestic rapier loom which is low rotary speed,low efficiency,high failure rate and poor quality of woven fabric has a certain gap with foreign rapier loom.This paper makes a research on conjugate cam weft insertion mechanism in order to improve the weaving performance and the market competition ability of the domestic rapier loom.The following works have been accomplished.The structural characteristics and technological requirements of weft insertion mechanism are analyzed.Motion equation of rapier head is derived according to the modified trapezoidal acceleration motion law.The motion of weft insertion mechanism is analyzed by Assur-group Method.According to the motion of the follower,the coordinate value of the conjugate cam profile and its related parameters are calculated,which provide the theoretical basis for the design of the mechanism.The kinetic energy and deformation energy of the weft insertion mechanism component discretized by finite element method which is equivalent to the beam element is calculated.The Lagrange equation of beam element is established and then the Lagrange equation of whole system is deduced.Using the ode45 solver,elastic deformation and dynamic stress of the component and natural frequency of the mechanism are analyzed by MATLAB.Changing the structural parameters of the component improve dynamic characteristics of weft insertion mechanism,which provide support for the structural optimization design of the mechanism.Weft insertion mechanism assembly modeled in SOLIDWORKS is imported into ADAMS to analyze the contact impact force of roller and conjugate cam and motion of rapier head.The effect of the flexibility of the rapier and the connecting rod on motion of rapier head is analyzed by the simulation of rigid flexible coupling.A method by increasing structure size of component to improve the stability of weft insertion motion is proposed.The natural frequency and modal vibration of the conjugate cam are analyzed by ANSYS,which provide guidance for the design of conjugate cam.